Timing of fuel injection systems



Nov. 9, 1948. D. E. MEl'TzLER TIMING 0F FUEL INJECTION SYSTEMS Filed .my 2s. 194s 2 Sheets-Sheet 1 www."

`mlllllllllIIHIIIIIIIIIHIII ATTORNEYS` Nov. 9, 1948. l D, E, ME|TZ|` ER 2,453,526

TIMING or FUEL INJECTIONV SYSTEMS YFiled .July 23. 1943 2 sheets-sheet 21 /0 7a l //6 58 l/0 Il ha FIG. 2

INVENTOR ATTORNEY Patentedl Nov. 9, 1948 UNITED sra-'resV PAT ENT o1-FICE 2,453,526 TIMING F FUEL INJECTION SYSTEMS Donald E. Meitzler, Manchester, Conn., assigner to United Aircraft Corporation,

East Hartford,

Conn., a corporation oi' Delaware Application July23, 1943, Serial No. 495,929

6 Claims. (Cl. 10S-154) plunger with respect to the oscillating stroke of y the pinion.

In this type of apparatus the injection of fuel isl controlled by the position of the injection plunger within the cylinder. and the changes in the position of the plunger stroke may be used for varying they period of fuel injection' into the engine cylinder. Another feature of this invention is an adjustment of the plunger stroke for changing the injection cycle. Another feature is the adjustment of the plunger stroke with respect to the stroke of the pinion by angular movement of a part of the connecting structure between the pinion and plunger.

Other objects and advantages will be apparent from the specification and claims, and from the accompanying drawing which illustrates what is nowconsidered to be a preferred embodiment of the invention.

Fig. 1 is a side elevation of the free-piston engine-and-compressor unit.

Fig. 2 is a sectional view through the restraining pinion and the injection pump.

The unit shown includes an engine cylinder I0 having reciprocating pistons l2 and I4 to which compressorV pistons I6 and I8 in cylinders 20 and 22 are integrally connected. Sleeves 24 and 26 attached to the compressor pistons complete the reciprocating piston assemblies. The sleeves in combination with stationary pistons 28 and 30 form air spring cylinders.

valves 42, also at opposite ends of the compressor cylinders, and passes through scavenge manifold 44 through ports 46 and 48 which are uncovered by pistons |2 and I4 at the end of the power stroke, thereby permitting air to be blownthrougl: the engine cylinder and exhaust ports 60 and 52 into exhaust `manifold 54. y

As shown in Fig. 2, pinion 36 is supported in a housing 56 forming partof the injection device which is mounted in a tubular bracket 58. Housing 56 provides a bearing for a. shaft 60 integral with the pinion. This shaft is also supported by a ring 62 in housing 56. A radial flange 64 on the shaft is held between the end of bearing 62 and a thrust ring 68 to prevent endwise movement of the pinion.

The inner surface of sleeve 60 is providedwith a.

helix 68 which engages several spaced shoes 10 on a cup 12 Vpositioned over acasing 14 in which an injection plunger 'I6 is movable. A coil spring 18,

moves the-cap axially to hold the shoes in contact with the helix. As the pinion oscillates, the

Vplunger 18 is moved longitudinally inits bore 80 in the casing 'l4 for injection of fuel into the engine. A coil spring 82 moves the plunger 16 on its return stroke. ,i

The injection system shown is ofthe accumulator type, and casing 14 has opposed accumulator chambers .84 and 86 interconnected -by a passage 88. Fuel from the end of bore 80 reaches chambers 84 and 86 through a groove 90 in an accumulator valve 92 which slides in a bore in a ring 96 in the casing 14. Fuelescapes from accumulator chambers through a passage 98 and past a check valve |00 tothe nozzle. |04. The accumulator valve 92 moves lengthwise to engage a seat |06 at the end of passage 98 or a seat |08 closing the groove 90. vCheck valve |00 is held against The piston assemblies are moved apart by the 1 burning of fuel injected into engine cylinder l0 by one or more devices 32. Air compressed in the air spring cylinderson the power stroke returns the piston assemblies. The assemblies are maintained at equal distances from the center of the engine cylinder by a linkage which may include racks 34 on the compressor pistons engaging opposite sides of a pinion 36. l

Intake manifold 38 conducts air to intake valves 40 through which air alternately enters opposite ends of the compressor cylinders.

The coinp pressed air leaves the cylinders through discharge bore of the oscillating pinion may be adjusted by itsseat by a spring |09 which determines the pressure at which injection of fuel fromchambers 84 and 86 is cut off.

Asthe plunger is moved on the injection stroke. fuel which was directed to the end of bore through an inlet port ||0 is forced into the accumulator chambers through groove until a discharge port ||2 is uncovered by a groove ||4 'in the plunger. This groove ||4 connects with the head of the plunger through a passage 4| I6 (shown. in dotted lines). When port |l2 is uncovered. the pressure at the end of the plunger drops suddenly so that valve 92 moves vagainst seat |08 and permits fuel to `discharge through the nozzle. A The position of the plunger stroke within the turning the cup 12 angularly. thereby changing the position of shoes I0 with respect to the helix. This adjustment may beeected by a gear |20 carried by a cap-122 onv housing 58.' This gear is splined to cup 12 and meshes with a worm |24 mounted in the cap. Worm I-Nh'as a shaft projecting'out of the housing (not shown) by which v the worm may-be turned manually or mechanically. When the angular position oi cup I2 is changed by turning the worm to vary the position of the plunger stroke, the point at which fuel injection occurs with respect to the emilie piston l o stroke will also be varied.

It is to be understood that the invention is not limited to the specinc embodiment herein illustrated and described, but may be used in other ways without departure from its spirit as dened by, the following claims.

I claim:

1. Fuel injectionapparatus for `a free-piston Aengine-'and-compr.essor unit having opposed P18- tons and a restraining linkage connecting said pistons including an oscillating pinion, said appawhen said groove and port are in communication, v a helix on said pinion and a cooperating follower connected to the plunger, and means including a gear and a cooperating pinion for turning the follower angularly to change the relative positions of the helix and plunger.

5. Fuel injection apparatus for a free-piston engine-and-compressor unit having opposed pis, tons and a restraining linkage connecting said pistons including an oscillating pinion, said apparatus includinga casing having a bore, a pump'v plunger longitudinally movable in said bore for pumping fuel into the unit. a port communicating with said bore, and a cooperating groove in said plunger'for procuring a change in the injection operation when said groove and port are in communication', said casing being located in part f -within the oscillating pinion with the longitudinal ratus including an injection plunger, a cylinder'in l l which said plungerreciprocates, said plunger and cylinder havingl cooperating injection control means dependent upon the longitudinal position of the plunger in the cylinder, means including a helix and follower connectingsaid pinion "and plungerfor reciprocating the plunger in response toosclllation of the pinion, and means for adjusting the longitudinal' position of the plunger with respect to said connecting means to shift the axis of the plunger parallel tothe axis of oscillar tion of the pinion, a helix and a cooperating follower connectingthe pinion and plunger for re- Aciprocating the plunger in response to oscillation of said ,.pinion, and means independent of the I pinion oscillation for adjusting the longitudinal position of the plunger with respect to said pinion,

. thereby shifting longitudinally the stroke of thel plunger. l 6. Fuel injection apparatus for a free-piston engine-and-compressor unit having opposed pistons and a restraining linkage connecting said pistons including an oscillating pinion,l said apparatus includingv a casing having a bore, a pump plunger stroke longitudinally within the cylinder.

2. Fuel injection apparatus for a free-piston engine-and-compressor unit having opposed pistons'` and a'restraining linkage connecting -said pistons including an oscillating pinion, said appalratus including a cylinder, a plunger longitudi- 'nally movable in said cylinder, a .port in said cylinder and a cooperating groove in said plunger for procuring-a change in the injection operation when said groove and port are in communication, a helix and a cooperating follower connecting the pinion and plunger for reciprocating the plunger plunger longitudinally movable in said bore for pumping fuel into the unit, a port communicating with said bore, and a cooperating groovein said' plunger for procuring a change in the injection operation when said groove and port arein communication, said casing being located in part within the oscillating pinion with the longitudinal axis of the plunger parallel to the axis of oscillation of the pinion, a helix on said pinion, and a cooperating follower engaging said helix, said follower being connected to the plunger and being movable axially through the pinion as the latter oscillates, and means for turningl the follower angularly to change the relative positions of the helix and follower, thereby shifting longitudinally the stroke of the plunger within the bore.

for procuring a change in the injection operation when saidgroove and port are in communication, a. helix on said pinion and a cooperating follower connected to the plunger, and means for turning the follower angularly to change the relative positions of the helix and plunger. thereby shifting longitudinally the stroke f the plunger.

4. Fuel injection apparatus for a free-piston engine-and-compressor unit havingr opposed pistons and 'a restraining linkage connecting said pistons including an oscillating pinion, said apparatus including a cylinder, a plunger longitudi-v nally movable in said cylinder, a port in said cylinder and a cooperating groove in said plunger for procuring a. change in the injection operation DONALD E. MEITZLER.

anFEnENcns CITED The following references are of record in the file of this patent:

. UNITED STATES PATENTS Number Name Date 1,704,325 Junkers Mar. 5, 1929 2,016,613 Pescara Oct. 8, 1935 2,038,442 Pescara Apr. 21. 1936 2,102,121 Janlcke Dec. 14, 1937 2,132,083 Pescara Oct. 4, 1938 2,222,260 Janicke Nov. 19, 1940 2,230,760 Pescara -.----l.--" Feb. 4, 1941 2.234.936 Streby Mar. 11, 1941 2,344,058 Pescara Mar.- 14,1944 2,368,013 Ford Jan. 23, 1945 FOREIGN PATENTS Number f Country Date Germany Apr. 15,1922 

